Insecticidal phenols

ABSTRACT

2,6-DI-(BRANCHED ALKYL)-4-(HALOVINYLTIO) PHENOL COMPOUNDS OF THE FORMULA   2-R1,4-((X-)2-C=CH-S-)PHENOL   WHEREIN R1 AND R2 ARE BRANCHED ALKYL GROUPS OF 3 TO 6 CARBON ATOMS AND X IS HYDROGEN, FLUORINE, CHLORINE BROMINE OR IODINE, WITH THE PROVISO THAT AT LEAST ONE X IS HALOGEN HAVE MORPHOGENETIC HORMONAL MIMETIC ACTIVITY ON MOSQUITOS. THE COMPOUNDS ARE PREPARED BY THE REACTION OF A 2,6-DI-(BRANCHED ALKYL) PHENOL AND A HALOVINYLSULFENYL HALIDE.

United States Patent 3,798,274 INSECTICIDAL PHENOLS Joseph E. Moore,Richmond, and Gustave K. Kohn,

Berkeley, Calif., assignors to Chevron Research Company, San Francisco,Calif. No Drawing. Filed Oct. 24, 1972, Ser. No. 300,082 Int. Cl. C07c149/36 U.S. Cl. 260-609 F 4 Claims ABSTRACT OF THE DISCLOSURE2,6-di-(branched alkyl)-4-(halovinylthio) phenol compounds of theformula 'BACKGROUND OF THE INVENTION Field of the invention The presentinvention is concerned with insecticidal compounds which havemorphogenetic hormonal mimetic activity. Compounds having m'orphogenetichormonal mimetic activity exert a disrupting influence upon the normaldevelopment of insects. These compounds interfew with the normalmetamorphosis of the pest insects and result in the formation ofindividual insects of the treated species which develop abnormally andare nonviable or sterile. This ultimately leads, indirectly at least, tothe destruction of the insect population.

Description of the prior art Chemical and Engineering News, Nov. 29,1971, pp. 9-10, discloses the use of2,6-di-t-butyl-4(a,u-dimethylbenzyl) phenol as a mosquito larvicide.

Japanese Pat. No. 16,970, issued May 11, 1971 (Chem. Abs. 75, 98317e[1971]) discloses the use of 2,6-di-tbutyl-4-phenylthiophenol as aninsecticide.

Summary of the invention It has now been found that 2,6-di-(branchedalkyl)-4- halovinylphenols are effective for the control of mosquitoswhen applied in insecticidally effective amounts to preadult mosquitos.

DESCRIPTION OF THE INVENTION The phenols of the invention arerepresented by the 'FormulaI I i. (I)

wherein R and R are branched alkyl groups of 3 to 6 carbon atomsattached to the aromatic ring through a secondary or tertiary carbonatom and X is hydrogen, fluorine, chlorine, bromine, or iodine, with theproviso that at least one X is a halogen. Preferably X is chlorine orbromine.

Representative branched alkyl groups which R and R may represent includes-propyl, s-butyl, t-butyl, t-amyl,

3,798,274 Patented Mar. 19, 1974 s-hexyl, etc. R and R may be the sameor different branched alkyl groups. Preferred R and R groups areattached to the aromatic ring through a secondary carbon atom (i.e., acarbon atom substituted with two alkyl groups) or a tertiary carbon atom(i.e., a carbon atom substituted with three alkyl groups).

Representative phenols of Formula I include2,6-di-t-butyl-4-(1-chlorovinylthio) phenol, 2,6-di-t-butyl-4-(2-chlorovinylthio) phenol, 2,6-di-t-butyl-4(2,2-dichlorovinylthio)phenol, 2,6-di-t-butyl-4-(1,2-dichlorovinylthio) phenol,2,6-di-t-amyl-4-(trichlorovinylthio) phenol, 2,6-di-secbutyl-4=(trichlorovinylthio) phenol, 2,6-diisopropyl4-(l bromovinylthio)phenol, 2,6-di-t-amyl-4-(Z-bromovinylthio) phenol,2,6-di-sec-hexyl-4(1,2-dibromovinylthio) phenol,2,6-di-t-butyl-4-(2,2-dibromovinylthio) phenol,2,6-diisopropyl-4-(tribromovinylthio) phenol, 2-t-butyl-6t-'amyl-4-(1-chloro-2-bromovinylthio) phenol, 2-t-butyl-6-t-butyl-4-(l-chloro-2,2-dibromovinylthio) phenol, 2-t-butyl-6-t-butyl-4-1-bron1o2,Z-dichlorovinylthio) phenol, 2,6-di-t-butyl-4-(l-fiuorovinylthio) phenol, 2,6-di-t-butyl-4-(l-iodovinylthio) phenol,2,6-di-t butyl-4-(Z-fiuorovinylthio) phenol,2,6-di-t-butyl-4-(2,2-difluorovinylthio) phenol, 2,6-di-t-but yl-4-(1-chloro-Z,2-difluorovinylthio) phenol, 2,6-di t-butyl-4(1-iodo-2,Z-dichlorovinylthio) phenol,2,6-di-t-butyl-4-(1-flu-oro-2,2-dichlorovinylthio) phenol,2,6-di-t-butyl-4-(1,2-difluorovinylthio) phenol,2,6-di-t-buty1-4-(trifluorovinylthio) phenol,2,6-di-t-butyl-4-(l-bromo-2,2-difiuorovinylthio) phenol,

and 2,6-di-t-butyl-4-(1-fluoro-2,2-dibromovinylthio) phenol.

The phenols of Formula I are prepared by the reaction of a 2,6-di(branched alkyl) phenol and a halovinylsulfenyl chloride as depicted inthe following Equation 1:

H0@ ox=ox,-s-o1 nos-ox=oxl 1101 where R R and X have the samesignificance as defined in Formula I.

The reaction depicted in Equation 1 is conducted by more or lessconventional procedures. The molar ratio of the phenol (H) to thesulfenyl halide (III) is substantially equimolar. The reaction isconducted in a solvent such as acetic acid. Reaction temperaturessuitably vary from 0 C. to 150 C. The product is isolated by conventional methods such as extraction, distillation, crystallization,etc.

The compounds of the invention are useful as morphogenetic hormonalmimetic insecticides, particularly against mosquitos such as Aedesaegypti, Culex pipinens, Quinque fasciatus and Culiseta inornara.

The compounds are very potent and are used at extremely lowconcentrations. For example, compositions containing ppm. to 0.01p.p.m., preferably from 5 p.p.m. to 0.1 ppm, are effective for thecontrol of insects However, the effective concentration depends in parton the mode of application and the particular insect.

The compounds may be applied in either liquid or solid formulations tothe pre-adult insects or their environment. For example, they may besprayed or otherwise applied directly to plants or aqueous bodies so asto effect control of insects coming into contact therewith.

Formulations of the compounds of this invention will comprise a toxicamount of one or more of the compounds and a biologically inert carrier.Usually they will also contain a wetting agent. Solid carriers such asclay, talc, sawdust, alfalfa meal, and the like may be used in suchformulations. Liquid diluents which may be used with these compoundsinclude Water and aromatic solvents. In addition these formulations maycontain other compatible pesticides, fillers, stabilizers, attractantsand the like.

The concentration of the active ingredient to be used with inertcarriers, either solid or liquid carriers, will be dependent upon manyfactors, such as the particular compound which is used, the carrier inor upon which it is incorporated, the method and conditions ofapplication, the insect species to be controlled, etc., the properconsideration of these factors being within the skill of those versed inthe art. In general, the toxic ingredients of this invention will beeffective in concentrations from about 0.0001 percent by weight to ashigh as 50 percent by weight or higher. Economically, of course, it isdesirable to use lower concentrations of this active ingredient. Thus,it is usually desirable to use less than 20 percent by weight of theactive ingredient in a particular composition.

The compounds of the invention are particularly useful in combinationwith mosquito lar-vicidal petroleum oil dispersions. Petroleum oilssuitable as mosquito larvicidal dispersions are known. Such hydrocarbonoils include mineral oils such as naphthenic base and paraffinic baselubricating oils, etc., as well as synthetic oils. Such hydrocarbon oilsare nonphytotoxic and generally contain not more than a few percentaromatics. Particularly suitable hydrocarbon oils have boiling pointsabove 350 to 400 F. and viscosities of from about 33 to 200 SSU at 100F.

The amount of the compound of the invention employed in petroleum oilgenerally ranges from 0.1% to by weight based on weight of oil. Thehydrocarbon oil dispersions containing the compounds of the inventionare contacted with or applied to the surface of the aqueous bodieswherein mosquito control is desired by conventional methods.

The terms insecticide and insect as used herein refer to their broad andcommonly understood usage rather than to those creatures which in thestrict biological sense are classified as insects. Thus, the term insectis used not only to include small invertebrate animals belonging to theclass Insect-a but also to other related classes of arthropods whosemembers are segmented invertebrates having more or fewer than six legs,such as spiders, mites, ticks, centipedes, worms and the like.

Example 1.-Preparation of 2,6-di-t-butyl-4- (trichlorovinylthio) phenolA solution of 19.8 g. (0.1 mol) trichlorovinylsulfenyl chloride in 30ml. acetic acid was added dropwise to a solution of 20.6 g. (0.1 mol)2,6-di-t-butylphenol in 50 ml. of acetic acid over a 1-hour period atambient temperature. Heat and gases were evolved. The reaction mixturewas stirred at about 25 C. overnight (about 16 hours). The reactionmixture was then distilled under reduced pressure to remove the aceticacid and low boiling materials (to an overhead temperature of 110 C./0.3 mm. of Hg). The pot residue solidified on cooling. The residue waschromatographed on silica gel (hexane eluant) to give the crude productas a yellow solid. Recrystallization from hexane gave product whichmelted at 7476 C.

Elemental analysis showed: Cale. (percent): CI, 28.9; S, 8.7. Found(percent): CI, 28.6; S, 8.9.

4 Example 2.Preparation of 2,6-di-sec.-butyl-4 (trichlorovinylthio)phenol By a procedure similar to that of Example 1,2,6-disec.-butyl-4-(trichlorovinylthio) phenol was prepared from2,6-di-sec.-butylphenol and trichlorovinylsulfenyl chloride. The productwas obtained as a yellow oil after chromatography on silica gel and hadthe following elemental analysis:

Calc. (percent): Cl, 28.9; S, 8.7. Found (percent): Cl, 28.8; S, 8.6.

Example 3 2,6-di-t-butyl-4-(trichlorovinylthio) phenol (Compound A) wastested as a morphogenetic hormonal mimetic insecticide against yellowfever mosquito larvae (Aedes aegypti) by the following procedure: Latefourth stage larvae of the mosquito are placed in a cup containing 200ml. of deionized water containing a known amount of the phenol compounddissolved therein. About 20 larvae are used per test. The larvae are fedand allowed to pupate. The live pupae are kept until the adult emerges.A count is made at each step for mortality, i.e., larvae, pupae andadult mortality. For comparison, 2,6-di-tbutyl-4-(a,ot-dimethylbenzyl)phenol (Compound B) was also tested. The concentration and the mortalitycounts are tabulated in Table I.

TABLE I Mortality Conc.,

p.p.m. Larvae Pupae Adults Total 2,6-di-t-butyl-4-(trichlorovinyl)phenol was tested for the control of Aedes aegypti larvae by a proceduresimilar to that above, except that the phenol/water solution wasprepared 13 days before infestation with the larvae. At a 0.3 p.p.m.concentration of the phenol, an pupae mortality count was observed.

Example 4.-Petroleum oil formulation A 1% by weight formulation of2,6-di-t-butyl-4-(trichlorovinylthio) phenol was prepared with an oilcomposition having 96.1% by weight of a petroleum oil having an aromaticcontent of 8.4% by weight and a vis cosity of 36.3 SSU at F., 0.9% byweight of ethoxylated dodecyl phenol (molecular Weight 526 and 6 molsethylene oxide per mol phenol) and 3% by weight of polyisobutenylsuccinic anhydride (molecular weight 950).

The oil formulation was tested for the control of Aedes aegypti larvaeby applying a thin film of the oil formulation to a container containing20 larvae and ml. of water. The larvae are fed and allowed to pupate.After two days, a count is made of larvae and pupae mortality. At adosage corresponding to 0.33 gallon/ acre, the larvae mortality was zeroand the pupae mortality was 95%.

Example 5 2,6-di-sec.-butyl 4 (trichlorovinylthio) phenol was tested asa morphogenetic hormonal mimetic insecticide against yellow fevermosquito larvae by a procedure identical to that of Example 3. At aconcentration of 1.7 p.p.m., the percent pupae mortality was 5%.

5 s We claim: 4. The compound of claim 1 being 2,6di-t-butyl-4- 1.Compounds of the formula (trichlorovinylthio) phenol.

References Cited HWOSLCBCXQ 5 UNITED STATES PATENTS I 3,155,733 11/1964Reifscheider 260-609 F 32 3,231,623 '1/19 66 Reifscheider 260-609 F h Rd R2 b h d 1k 1 f 3 t 6 b 3,523,146 8/1970 Braus 260-609 F w erem an areranc e a y o 0 car on atoms attached to the aromatic ring through asecondary 10 FOREIGN PATENTS or tertiary carbon atom and X is hydrogen,fluorine, 245,092 11/1969 U.S.S.R. 260-609 F chlorine, bromine, oriodine, with the proviso that at least one X is halogen. LEWIS GOTIS,Primary Examiner 2. The compound of claim 1 wherein X is chlorine orPHILLIPS, Assistant i bromine. 15

3. The compound of claim 2 wherein R and R are ter- US. Cl. X.R. tiaryalkyl. 424-337

